Six cases of cutaneous myiasis occurred in three groups of visitors to Guatemala between February and May 1978. Attack rates ranged from 12% to 50%. Furuncular lesions were generally multiple and involved both exposed and usually unexposed areas of the body. Parasitic fly larvae recovered from two patients were identified as the botfly, Dermatobia hominis. Botfly infestation is endemic in areas of Central and South America and is acquired indirectly through the bite of carrier arthropods, including mosquitoes. Although reports of cases in North Americans visting endemic areas are rare, the condition is probably much more common in such persons than it is currently believed to be. A history of travel to Central or South America should suggest the diagnosis.